diff --git a/Source/OpenTK/Audio/AudioContext.cs b/Source/OpenTK/Audio/AudioContext.cs
index af74c86c..cbb97761 100644
--- a/Source/OpenTK/Audio/AudioContext.cs
+++ b/Source/OpenTK/Audio/AudioContext.cs
@@ -63,15 +63,11 @@ namespace OpenTK.Audio
 
         /// <summary>Constructs a new AudioContext, using the default audio device.</summary>
         /// <exception cref="NotSupportedException">Occurs when no audio devices are available.</exception>
-        public AudioContext()// : this(available_devices.Count > 0 ? available_devices[0] : null, 0, 0, false, 0) { }
-        {
-            if (!openal_supported)
-                throw new DllNotFoundException("openal32.dll");
-            CreateContext(null, 0, 0, false, 0);
-        }
+        public AudioContext()
+            : this(null, 0, 0, false, true) { }
 
         #endregion
-#if false
+
         #region public AudioContext(string device)
 
         /// <summary>Constructs a new AudioContext, using the specified audio device.</summary>
@@ -80,7 +76,7 @@ namespace OpenTK.Audio
         /// Use AudioContext.AvailableDevices to obtain a list of all available audio devices.
         /// devices.
         /// </remarks>
-        public AudioContext(string device) : this(device, 0, 0, false, 0) { }
+        public AudioContext(string device) : this(device, 0, 0, false, true) { }
 
         #endregion
 
@@ -94,7 +90,7 @@ namespace OpenTK.Audio
         /// devices.
         /// </remarks>
         /// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
-        public AudioContext(string device, int freq) : this(device, freq, 0, false, 0) { }
+        public AudioContext(string device, int freq) : this(device, freq, 0, false, true) { }
 
         #endregion
 
@@ -110,7 +106,7 @@ namespace OpenTK.Audio
         /// </remarks>
         /// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
         public AudioContext(string device, int freq, int refresh)
-            : this(device, freq, refresh, false, 0) { }
+            : this(device, freq, refresh, false, true) { }
 
         #endregion
 
@@ -127,7 +123,7 @@ namespace OpenTK.Audio
         /// </remarks>
         /// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
         public AudioContext(string device, int freq, int refresh, bool sync)
-            : this(available_devices[0], freq, refresh, sync, 0) { }
+            : this(available_devices[0], freq, refresh, sync, true) { }
 
         #endregion
 
@@ -138,7 +134,7 @@ namespace OpenTK.Audio
         /// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
         /// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
         /// <param name="sync">Flag, indicating a synchronous context.</param>
-        /// <param name="maxSends">Number of auxilliary send slots for the EFX extensions. Can be 0 (use driver default) or higher.</param>
+        /// <param name="enableEfx">Indicates whether the EFX extension should be initialized, if present.</param>
         /// <exception cref="ArgumentNullException">Occurs when the device string is invalid.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Occurs when a specified parameter is invalid.</exception>
         /// <exception cref="InvalidAudioDeviceException">
@@ -158,13 +154,13 @@ namespace OpenTK.Audio
         /// Values higher than supported will be clamped by the driver.
         /// </para>
         /// </remarks>
-        public AudioContext(string device, int freq, int refresh, bool sync, int maxSends)
+        public AudioContext(string device, int freq, int refresh, bool sync, bool enableEfx)
         {
-            CreateContext(device, freq, refresh, sync, maxSends);
+            CreateContext(device, freq, refresh, sync, enableEfx);
         }
 
         #endregion
-#endif
+
         #endregion
 
         #region --- Private Methods ---
@@ -219,7 +215,7 @@ namespace OpenTK.Audio
 
         #endregion
 
-        #region void CreateContext(string device)
+        #region CreateContext
 
         /// <private />
         /// <summary>Creates the audio context using the specified device.</summary>
@@ -227,7 +223,7 @@ namespace OpenTK.Audio
         /// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
         /// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
         /// <param name="sync">Flag, indicating a synchronous context.</param>
-        /// <param name="maxEfxSends">Number of auxilliary send slots for the EFX extensions. Can be 0 (use driver default) or higher.</param>
+        /// <param name="enableEfx">Indicates whether the EFX extension should be initialized, if present.</param>
         /// /// <exception cref="ArgumentOutOfRangeException">Occurs when a specified parameter is invalid.</exception>
         /// <exception cref="AudioDeviceException">
         /// Occurs when the specified device is not available, or is in use by another program.
@@ -246,14 +242,16 @@ namespace OpenTK.Audio
         /// Values higher than supported will be clamped by the driver.
         /// </para>
         /// </remarks>
-        void CreateContext(string device, int freq, int refresh, bool sync, int maxEfxSends)
+        void CreateContext(string device, int freq, int refresh, bool sync, bool enableEfx)
         {
+            if (!openal_supported)
+                throw new DllNotFoundException("openal32.dll");
+            
             if (version == Version.OpenAL11 && available_devices.Count == 0)    // Version.OpenAL10 does not support device enumeration.
                 throw new NotSupportedException("No audio hardware is available.");
             if (context_exists) throw new NotSupportedException("Multiple AudioContexts are not supported.");
             if (freq < 0) throw new ArgumentOutOfRangeException("freq", freq, "Should be greater than zero.");
             if (refresh < 0) throw new ArgumentOutOfRangeException("refresh", refresh, "Should be greater than zero.");
-            if (maxEfxSends < 0) throw new ArgumentOutOfRangeException("maxEfxSends", maxEfxSends, "Should be greater than zero.");
 
             if (!String.IsNullOrEmpty(device))
                 device_handle = Alc.OpenDevice(device);
@@ -289,13 +287,14 @@ namespace OpenTK.Audio
             attributes.Add((int)AlcContextAttributes.Frequency);
             attributes.Add(sync ? 1 : 0);
 
-            if (maxEfxSends > 0)
+            if (enableEfx && Alc.IsExtensionPresent(device_handle, "ALC_EXT_EFX"))
             {
-                throw new NotImplementedException();
-                //if (Alc.IsExtensionPresent(device_handle, "ALC_EXT_EFX"))
-                //attributes.Add((int)AlcContextAttributes.MaxAuxilliarySends);
-                //attributes.Add(maxEfxSends);
+                int num_slots;
+                Alc.GetInteger(device_handle, AlcGetInteger.EfxMaxAuxiliarySends, 1, out num_slots);
+                attributes.Add((int)AlcContextAttributes.EfxMaxAuxiliarySends);
+                attributes.Add(num_slots);
             }
+            attributes.Add(0);
 
             context_handle = Alc.CreateContext(device_handle, attributes.ToArray());